Arlen Specter didn't just rescue his own re-election bid by switching to the Democratic Party last week: he may have pulled the rug out from GOP rival Pat Toomey and cleared the way for Tom Ridge, the former governor and America's first Department of Homeland Security secretary, to secure the Republican nomination in Pennsylvania's 2010 Senate race.

According to a new Quinnipiac University poll, Specter the Democrat leads Republican Toomey 53-33 percent in a general election matchup. Ridge, however, trails Specter by just 46-43 percent. Until Specter dropped, Ridge's name wasn't being mentioned in the crowded primary, at least as far as I knew...

Toomey made it impossible for Specter to win re-election as a Republican, smashing him in GOP primary polls and accusing him of being too liberal. There's a lot of time for Toomey to campaign and potentially change these numbers, but if Pennsylvania Republicans value general-election viability over the economic conservatism Toomey offers, things may be tougher for both Specter and Toomey.